1. Field of the Invention
The present invention relates generally to an ambient light detecting apparatus and more particularly to an ambient light detecting apparatus which controls the initial application of electrical power to an electrical load responsive to the ambient light conditions and retains application of the power to the electrical load notwithstanding the ambient light conditions.
2. Description of the Prior Art
In the prior art there are various mechanical clock timers including electrical clocks with switch means to control application of electrical power to an external load. If the power source controlling the timer is interrupted, then the mechanical clock timer fails. Further, these types of devices generally require generous application of power in order to be operational.
Also, the prior art includes photodetector on-off devices having no timing circuits but are primarily simplified to turn on when the ambient light decreases below a certain level and turn off when the light returns to a certain level. Further, clock timers in the prior art include microprocessors which count the alternating current line cycle as a clock. The microprocessor is programmable to turn on and off. However, it is not fail-safe and if alternating current power is interrupted, the entire memory and program is lost.